It was early found by the keen-eyed gentlemen who analyzed ciphers that if one took ten thousand words of any language and counted the letters in them the number of times that any one letter would recur would be found practically identical with their recurrence in any other ten thousand words. From this discovery the experts made frequency tables, which show just how many times one may expect to find a letter e or any other letter in a given number of words or letters. These tables were made for ten thousand letters and for two hundred letters, so that one might get an idea how often to expect to find given letters in both long and short messages or documents. Thus we find the following result: _Letters_ 10000 200 A 778 16 B 141 3 C 296 6 D 402 8 E 1277 26 F 197 4 G 174 3 H 595 12 I 667 13 J 51 1 K 74 2 L 372 7 M 288 6 N 686 14 O 807 16 P 223 4 Q 8 .. R 651 13 S 622 12 T 855 17 U 308 6 V 112 2 W 176 3 X 27 .. Y 196 4 Z 17 .. It is found that in any text the vowels A E I O U represent 38.37 per cent; that the consonants L N R S T represent 31.86 per cent, and that the consonants J K Q X Z stand for only 1.77 per cent. One doesn’t want to shy away from these figures as being dry and dull, because they form part of a story as interesting as any detective narrative that was ever penned by a Conan Doyle. For the usual purposes of figuring a cipher the first group is given the value of 40 per cent, the second group 30 per cent, and the last 2 per cent. And then one is introduced to the order of frequency in which letters appear in ordinary text. It is: E T O A N I R S H D L U C M P F Y W G B V K J X Z Q. Tables are then made for kinds of matter that is not ordinary, taken from various kinds of telegraphic and other documents, which will alter only slightly the percentage values of the letters as shown in a table from ordinary English. Having gone along thus far, the expert figures how many times he can expect to find two letters occurring together. These are called digraphs, and one learns that AH will show up once in a thousand letters, while HA will be found twenty-six times. These double-letter combinations form a separate table all of their own, and the common ones are set aside, as TH, ER, ON, OR, etc., so they can be readily guessed or mathematically figured against any text. Tables of frequency are figured out for the various languages, particularly German, and the ciphers are divided into two chief classes, substitution and transposition. The writer in _The Press_ says: